It may be noted that in both schemes part of the syngas’s energy content
(30–50%) is lost during conversion into liquid transport fuel. It is apparent
from Table 9.4 that this loss in conversion from biomass to methanol or
ethanol can be as high as 50%, and further loss can occur when the methanol
is converted into a transport fuel like gasoline. For this reason, when we consider
the overall energy conversion efficiency of a car run on biogas and
compare that with an electric car, the former shows a rather low fuel-to-wheel
energy ratio.